How long, to the nearest day, until it is safe to swim again will be 156 days
Let x represent number of day until it is safe to swim again
First step
=2000 *1/2^x
100=2000 *0.5^x
0.05=0.5^x
Second step
Log 0.05=xLog 0.5
Log 0.05/L0g 0.5=x
x=36 days* Log 0.05/L0g 0.5
x=36 days*43.22
x=156 days
Inconclusion How long, to the nearest day, until it is safe to swim again will be 156 days
Learn more about radioactive element here:
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No idea how to do
[tex]\frac{4r + 20}{r + 5}[/tex]
when r ≠ 5 ?
Factorize the numerator:
4r + 20 = 4r + 4×5 = 4 (r + 5)
I think you meant to say r ≠ -5, which means r + 5 ≠ 0, so that the denominator is never zero and so the expression is defined (no division by zero). This lets you cancel the factor of r + 5 in the numerator with the one in the denominator:
(4r + 20)/(r + 5) = 4 (r + 5)/(r + 5) = 4
Jeanette wants to raise $3,200 in a marathon fundraiser. Her sponsers will donate
$35 for each (whole) kilometer she runs this summer.
The minimum amount Jeanette will have to run to reach her goal of $3, 200 is
kilometers.
Total amount she wants to raise = $3200
Amount she'll get for each kilometer = $35
So, number of kilometers she need to run
= Total amount she wants to raise/Amount she'll get for each kilometer
= $3200/$35
= 91.42....
Since her sponser is will donate only for whole kilometers she'll have to run 92 km.
Determine the value of K that will cause f(x)=Kx^2+4x-3 to intersect the line g(x)=2x-7 at one point. SHOW ALL YOUR STEPS, DON'T USE DECIMALS INSTEAD USE FRACTIONS PLEASE!!!!!
Given:
The function are:
[tex]f(x)=Kx^2+4x-3[/tex]
[tex]g(x)=2x-7[/tex]
The graph of f(x) intersect the line g(x) at one point.
To find:
The value of K.
Solution:
The graph of f(x) intersect the line g(x) at one point. It means the line g(x) is the tangent line.
We have,
[tex]f(x)=Kx^2+4x-3[/tex]
Differentiate this function with respect to x.
[tex]f'(x)=K(2x)+4(1)-(0)[/tex]
[tex]f'(x)=2Kx+4[/tex]
Let the point of tangency is [tex](x_0,y_0)[/tex]. So, the slope of the tangent line is:
[tex][f'(x)]_{(x_0,y_0)}=2Kx_0+4[/tex]
On comparing [tex]g(x)=2x-7[/tex] with slope-intercept form, we get
[tex]m=2[/tex]
So, the slope of the tangent line is 2.
[tex]2Kx_0+4=2[/tex]
[tex]2Kx_0=2-4[/tex]
[tex]x_0=\dfrac{-2}{2K}[/tex]
[tex]x_0=-\dfrac{1}{K}[/tex]
Putting [tex]x=x_0,g(x)=y_0[/tex] in g(x), we get
[tex]y_0=2x_0-7[/tex]
Putting [tex]x=-\dfrac{1}{K}[/tex] in the above equation, we get
[tex]y_0=2(-\dfrac{1}{K})-7[/tex]
[tex]y_0=-\dfrac{2}{K}-7[/tex]
Putting [tex]x=-\dfrac{1}{K}[/tex] and [tex]f(x)=-\dfrac{2}{K}-7[/tex] in f(x).
[tex]-\dfrac{2}{K}-7=K\left(-\dfrac{1}{K}\right)^2+4(-\dfrac{1}{K})-3[/tex]
[tex]-\dfrac{2}{K}-7=\dfrac{1}{K}-\dfrac{4}{K}-3[/tex]
[tex]-\dfrac{2}{K}-7=\dfrac{-3}{K}-3[/tex]
Multiply both sides by K.
[tex]-2-7K=-3-3K[/tex]
[tex]-2+3=7K-3k[/tex]
[tex]1=4k[/tex]
[tex]\dfrac{1}{4}=K[/tex]
Therefore, the value of K is [tex]\dfrac{1}{4}[/tex].
Find the slope
of the line passing through the points (3, 4)
and
(8, -3).
Answer:
-7/5
Step-by-step explanation:
I think let me know
Answer:
7/-5 or -7/5
Step-by-step explanation:
This shall be quite an easy problem, I shall be doubting that this is high school, however, I am happy to aid :)
We shall begin by labeling the points given to us to prepare for inputting the values in the slope formula
(3,4). (8,-3)
x1,y1 x2,y2
Slope Formula:
y1 - y2
x1 - x2
Inputting the values:
4 - (-3)
3 - 8
Solve:
7
-5
The slope of the line passing through the points (3,4) and (8,-3) shall be 7/-5 or -7/5 negatives shall go both ways of fractions
1. Una empresa realizó una encuesta a 250 personas para saber qué programa de televisión prefieren ver en domingo. Se les dieron 3 opciones: deportes, películas o musicales. El resultado de la encuesta fue: 130 personas prefieren deportes; 80 prefieren ver películas; 40, musicales; 25 prefieren deportes y películas; 20, películas y musicales; 10, deportes y musicales; y sólo a 6 personas les gustan los tres tipos de programas. a) ¿Cuántas prefieren ver sólo deportes? b) ¿Cuántas prefieren ver sólo un programa de televisión? c) ¿Cuántas prefieren ver películas o musicales?
Answer:
A) 89 personas prefieren ver sólo deportes.
B) 122 personas prefieren ver sólo un programa de televisión
C) 33 personas prefieren ver películas o musicales.
Step-by-step explanation:
Dado que una empresa realizó una encuesta a 250 personas para saber qué programa de televisión prefieren ver en domingo, y se les dieron 3 opciones: deportes, películas o musicales, donde el resultado de la encuesta fue: 130 personas prefieren deportes; 80 prefieren ver películas; 40, musicales; 25 prefieren deportes y películas; 20, películas y musicales; 10, deportes y musicales; y sólo a 6 personas les gustan los tres tipos de programas; para determinar A) cuántas prefieren ver sólo deportes, B) cuántas prefieren ver sólo un programa de televisión; y C) cuántas prefieren ver películas o musicales, se deben realizar los siguientes cálculos:
A)
130 - 25 - 10 - 6 = 89
B)
80 - 25 - 20 - 6 = 29
40 - 20 - 10 - 6 = 4
89 + 29 + 4 = 122
C)
29 + 4 = 33
Dan invests £18790 into his bank account. He receives 5.9% per year simple interest. How
much will Dan have after 2 years? Give your answer to the nearest penny where appropriate.
Answer: £21007.22
Step-by-step explanation:
First, find the interest amount using the formula SI = (P × R × T) / 100.
SI = interest amount P = principle amount = £18790R = interest rate(in percentage) = 5.9T = time(in years) = 2SI = (P × R × T) / 100 = (18790 × 5.9 × 2)/100 = 221722/100 = £2217.22
The total amount = principle amount + interest amount
= £18790 + £2217.22 = £21007.22
Zoe and Hanna share tips in the ratio 3:7
Last week Zoe received £24
How much did Hanna receive last week?
Answer:
56
Step-by-step explanation:
Zoe : hanna
3 7
Zoe got 24
3*8 = 24
so multiply each side by 8
Zoe : hanna
3*8 7*8
24 56
Hanna got 56
Please help me solve this
Answer:
The 2nd one is 3x+1
The 3rd answer is x+3
Step-by-step explanation:
Given g(x)=4x-1 and f(x)=x-2
Subtracting both
4x-1-(x-2)=4x-1-x+2=x(4-1)+(2-1)=3x+1
The next one is 3x+1-(2x-2)=3x+1-2x+2=x+3
The width of a rectangle is twice as long as the length. if the length is increased by 50% and the width is decreased by 20%, the perimeter becomes 248. find the width and length of the original rectangle.
Answer:
Step-by-step explanation:
The percents here make this more tricky than it originally seems to be. We'll make a table and see where it takes us:
original new
length
width
And we'll fill it in according to our rules given. Starting with the original, we are told that the width is twice as long as the length. We don't know the length, so we'll call that L, and if the width is twice that, the width is 2L:
original new
length L
width 2L
Now here's the tricky part. What I'm going to do is fill in the "new" column with the expressions and then we'll simplify them in the next step.
The length is increased by 50%. So we have 100% of the original length and we are adding another 50% to that:
original new
length L 100%L + 50%L
width 2L
The width is decreased by 20%, so we have 100% of 2L and we are subtracting 20% of 2L from that:
original new
length L 100%L + 50%L
width 2L 100%(2L) - 20%(2L)
And now we'll simplify that "new" column:
original new
length L 150%L = 1.5L
width 2L 80%(2L) = 160%L = 1.6L
Now we're ready for the perimeter part. The formula for the perimeter of a rectangle is P = 2L + 2w, so filling in from our "new" column, since 248 is the perimeter given for AFTER the rectangle's length and width are manipulated:
248 = 2(1.5L) + 2(1.6L) and
248 = 3L + 3.2L and
248 = 6.2L so
L = 40 and that means that w = 80 (because in the "original" column, the width is twice the length)
Find the value of both variables.
[tex] \cos(45) = \frac{5 \sqrt{2} }{x} \\ \frac{1}{ \sqrt{2} } = \frac{5 \sqrt{2} }{x} \\ x = 10 \\ \\ \tan(45) = \frac{y}{5 \sqrt{2} } \\ 1 = \frac{y}{5 \sqrt{2} } \\ y = 5 \sqrt{2} [/tex]
I hope I helped you ^_^
Jack rides his bike 4 miles in 1/3 of an hour. What is jack unit rate in miles per hour?
Answer:
12 miles
Step-by-step explanation:
1/3 of an hour = 20 minutes = 4 miles
1 minute = 4/20 miles
60 minutes = 4/20 x 60 miles
= 4 x 3 miles
= 12 miles
60 minutes = 1 hour
=> 1 hour = 12 miles
Jacks unit rate is 12 miles/hr
Answer:
12
Step-by-step explanation:
There are two ways of doing this problem. I think the easiest way is to use a decimal in the denominator and round
4/0.333333333 = 12.000000001
The answer is obviously meant to be 12.
The other way is more sophisticated, but more accurate.
4/1 // 1/3 This is a 4 tier fraction. The rule is to invert the denominator (turn the bottom fraction upside down) and multiply.
4/1 * 3/1 = 12
The first method is easier to understand. The second is more accurate and more useful for physics.
6.7.35
Question Help
As(t)
800-
A toy rocket is launched from the top of a building 360
feet tall at an initial velocity of 112 feet/second. The
height of the rocket t seconds after launch is given by
the equation s(t)= - 16t2 + 112t+ 360. When does the
rocket reach its greatest height? What is the greatest
height?
600-
400-
200-
0-
0 1
8 9 10
The rocket reaches its greatest height at
feet after
second(s)
Answer:
Step-by-step explanation:
This is most easily solved with calculus, believe it or not. It is way more direct and to the point, with a whole lot less math!
The position function is given. The velocity function is the first derivative of the position, so if we find the velocity function and set it equal to 0, we can solve for the amount of time it takes for the rocket to reach its max height. Remember from physics that at the top of a parabolic path, the velocity is 0.
If:
[tex]s(t)=-16t^2+112t+360[/tex], then the velocity function, the first derivative is:
v(t) = -32t + 112 and solve for t:
-112 = -32t so
t = 3.5 seconds. Now we know how long it takes to get to the max height, we just need to find out what the max height is.
Go back to the position function and sub in 3.5 for t to tell us that position of the rocket at 3.5 seconds, which translates to the max height:
[tex]s(3.5)=-16(3.5)^2+112(3.5)+360[/tex] and
s(3.5) = 206 feet. I imagine that your answer, if you had to choose one from the list, would be 200 feet, rounded a lot.
Find the distance between the
following points using the
Pythagorean theorem: (5, 10)
and (10, 12)
Answer:
[tex]\displaystyle d = \sqrt{29}[/tex]
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightAlgebra I
Coordinates (x, y)Algebra II
Distance Formula: [tex]\displaystyle d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}[/tex]Step-by-step explanation:
*Note:
The distance formula is derived from the Pythagorean Theorem.
Step 1: Define
Identify
Point (5, 10)
Point (10, 12)
Step 2: Find distance d
Substitute in points [Distance Formula]: [tex]\displaystyle d = \sqrt{(10 - 5)^2 + (12 -10)^2}[/tex][√Radical] (Parenthesis) Subtract: [tex]\displaystyle d = \sqrt{5^2 + 2^2}[/tex][√Radical] Evaluate exponents: [tex]\displaystyle d = \sqrt{25 + 4}[/tex][√Radical] Add: [tex]\displaystyle d = \sqrt{29}[/tex]Instructions: Point T is the centroid. Find TE if XE= 21.
Answer:
TE = 7
Step-by-step explanation:
The centroid divides a median in this ratios 1/3 and 2/3. In particular
XT = 2/3 XE
XT = 2/3 * 21
XT = 14
TE = 7
Explain the relationship of the meaning of the word isometric to the properties of an isometric or rigid transformation
Step-by-step explanation:
The iso parts of isometric means same, and It is similar becuase rigid trtransformation and the metric parts means measure. Basically isometric means same measure. Rigid transformation preserve "same measures" like angles and side lengths.
ASAP HELP!! PLEASEEEE!!
Answer:
Step-by-step explanation:
5.1, please this is just a guess from using my head to calculate
Next year, air fares will rise by 3%.
Calculate the new price of a R 1 400 ticket.
9514 1404 393
Answer:
₹1442
Step-by-step explanation:
The new price will be 1+3% = 1.03 times the old price.
₹1400 × 1.03 = ₹1442
[tex]\text{Solve for 'x':}\\\\3(x+1)=12+4(x-1)[/tex]
Hi there!
»»————- ★ ————-««
I believe your answer is:
[tex]x = -5[/tex]
»»————- ★ ————-««
Here’s why:
⸻⸻⸻⸻
[tex]\boxed{\text{Solving for 'x'...}}\\\\3(x+1)=12+4(x-1)\\----------\\\rightarrow 3x + 3 = 12 + 4x - 4\\\\\rightarrow 3x + 3 = 12 -4+4x\\\\\rightarrow 3x + 3 = 8 + 4x\\\\\rightarrow 3x + 3 = 4x + 8\\\\\rightarrow3x + 3 -3 = 4x + 8 - 3\\\\\rightarrow 3x = 4x + 5\\\\\rightarrow 3x - 4x = 4x - 4x + 5\\\\\rightarrow -x = 5\\\\\rightarrow \frac{-x=5}{-1}\\\\\rightarrow \boxed{x = -5}[/tex]
⸻⸻⸻⸻
»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
Answer:
x=-5Step-by-step explanation:
3(x+1)=12+4(x-1)
3(x+1)=8+4x
3x+3=8+4x
3x+3−4x=8
-x+3=8
-x=8-3
-x=5
-x(-1)=5(-1)
-x(-1)=-5
x=-5
what is the solution to this equation?
5x-4+3x=36
A. x=16
B. x=5
C. x=20
D. x=4
B. x = 5
tip : if in a rush just plug in the number and see if its true
8x - 4 = 36
x = 5
factor x^2-3x-28 using the x method
Answer:
[tex] {x}^{2} - 7x + 4x - 28 \\ = x(x - 7) + 4(x - 7) \\ = (x - 7)(x + 4)[/tex]
What’s the answer? I don’t understand the question and I came to see if you all can help
Answer:
15/2 that is the answer man
similar right triangles, i need help with this please
Answer:
Step-by-step explanation:
the answer is a)
Please hurry I will mark you brainliest
What is the slope of this?
Answer:
Step-by-step explanation:
you can use the rise over run technique, where you count how many units you go down or up, left or right to get to the next point. or use the slope formula :
(y2-y1)/(x2-x1)
the pairs given :
(1,6) and (3,2)
(2-6)/(3-1) = -4/2 = -2
-2 is the slope. the line is going downwards so there is a negative slope
The measure of two complementary angles are 2x degree and 3x degree, then value of x is
Answer:
2x+3x=90
or ,5x=90
or,x=90/5
X=18
Answer:
90/5=18 degrees
Step-by-step explanation:
in how many ways can 10 people be divided into three groups of 2, 3, and 5 people respectively
Answer:
2520 ways
Step-by-step explanation:
Given
[tex]n = 10[/tex]
[tex]r = (2,3,5)[/tex]
Required
The number of selection
First, select 2 people from 10 in 10C2 ways.
There are 8 people, left.
Next, select 3 people from 8 in 8C3 ways.
There are 5 people left.
Lastly, select 5 from 5 in 5C5 ways
So, we have:
[tex]Total = ^{10}C_2 * ^8C_3 * ^5C_5[/tex]
Using combination formula
[tex]Total = 45 * 56 * 1[/tex]
[tex]Total = 2520[/tex]
The number of music CDs sold in 1993 by one company was approximately 2.3×10^6.The number of music CDs sold by the same company in 2001 was approximately 7.9×10^7. What is the difference in CDs sold between 1993 and 2001?
Answer:
84%
Step-by-step explanation:
I'm not sure how I got that answer but I'm just smart like that. I'm sorry I couldn't give a better explanation. I'm in a bit of a rush but I hope this answer is helpful to you. Percentage was the only way I could think of. Sorry again.
The difference between CDs sold between 1993 and 2001 will be 76.7 × 10⁵.
What is subtraction?To subtract in mathematics is to take something away from a group or a number of objects.
In another meaning subtraction is a mathematical operation such that two values are going to subtract and give a resultant value.
The group's total number of items decreases or becomes lower when we subtract from it.
Given that sell of CDs in 1993 is 2.3 × 10⁶.
Sell of CDs in 2001 is 7.9 × 10⁷.
The difference between sell is = 7.9 × 10⁷ - 2.3 × 10⁶
⇒ 76.7 × 10⁵ hence it will the correct option.
For more about subtraction,
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Can someone please help me with this I’m struggling
Answer:
Equation: [tex]70=(x+3)x[/tex]
x = -10 or x = 7
x = 7 (width can't be negative)
x + 3 = 10
Step-by-step explanation:
Represent the width of the rectangle by x. "The length of a rectangle EXCEEDS the width by 3" means the length is 3 LONGER than the width, so the length is represented by the expression x + 3.
Area = (length)(width)
70 = (x + 3)x
Multiply out the right side.
[tex]70=x^2+3x\\x^2+3x-70=0[/tex]
Factor the left side.
[tex](x+10)(x-7)=0[/tex]
Each binomial could equal 0, so
[tex]x+10=0 \text{ or }x-7=0\\x=-10\text{ or }x=7[/tex]
The negative solution does not make sense as the width of a rectangle.
x = 7, making the length, x + 3 = 10
Answer:
Pls mark this as brainiest
Step-by-step explanation:
Area of the rectangle = length x breadth
consider 'x' to be width
therefore length = x+3
area = (x+3)*x
Area = 70 square
x = 7
x+3 = 7+3
= 10
verification
7 x 10
= 70
what is the square root of 25
the answer would be 5 because 5*5 or 5 squared (5^2) is equal to 25, hope this helps!
Graph the following equations by plotting 3 points and then connecting the points to form a line. Show your work to find the 3 points and then list the ordered pairs you used as part of your answer.
Answer:
The way I would tackle these types of problems would be to make a table, then graph the points using the results I get.
Step-by-step explanation:
So explaining the table is kinda hard since I suck at explaining, so I've attached a file showing the table I've made for number 1.
First Step:
Make the table. Make it a 3x4 table. For the top row, put y, the equation (I put 'y=2x' as shown in number 1), then x. Then for the left column, go down by one box, then put: -1, 0, 1. Really, you can put any numbers, but to make it easy for yourself, just write the numbers I've listed. These will be your y-values you'll be substituting.
Second Step:
a.) Plugging in the numbers. For the middle column, I've put down y=2x in each box, as shown in my table. Then for each of those boxes, plug in the numbers to the left of them and substitute them for the y-value. For example, look at the second row. The left box has '-1', so I replaced the 'y' in the equation and got '(-1)=2x'.
b.) After substituting the y-values, solve for x. For this case, you'll need to divide both sides by 2. If it doesn't make much sense, think about a seesaw. If you have 5 pounds on both sides, the seesaw will stay balanced. Add an additional 5 pounds to one side, then the seesaw will start tipping towards the heavier sides. So in order to keep an equation balanced, you must do any action to both sides of the equation. After diving both sides by 2, you'll get the value for x.
Final Step:
After finding the x-values for each of the y-values, it's time to graph the equations. Remember, x is left to right and y is down to up. To graph them, let's use the second row for example. y=-1 and x=-0.5. So all you need to do is to start from the origin (0,0), then go half a unit to the left, as x is negative, then go a unit down, as y is negative, then make a point. The rest should be pretty straight forward.
After making all three points, just get a ruler or any straight edge, then align it along those three points, then just make a line, and boom! You've solved number 1! For the purpose of saving my time, I'm pretty sure you can solve the rest using what I've just told you. Good luck!
Sameera purchased 3 (1/2) kg of apples and 4 (3/4) kg of oranges. What is the total weight of fruits purchased by her ?
Answer:
8 1/4 kg
Step-by-step explanation:
Add the weight of the fruits together
3 1/2 + 4 3/4
Get a common denominator of 4
3 2/4 + 4 3/4
7 5/4
7 4/4 + 1/4
8 1/4 kg
